我有一台 debian 11 机器，我在其上安装了 KVM，并且我还想安装 virt-manager，但是我得到了：
The following packages have unmet dependencies:
python3-libxml2 : Depends: libpython3.7 (>= 3.7.0) but it is not installable
E: Unable to correct problems, you have held broken packages.
当我尝试安装 libpython3.7 时，出现了以下信息：
Package libpython3.7 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'libpython3.7' has no installation candidate
奇怪的是，我已经拥有最新的 python 3：
python3
Python 3.9.2 (default, Feb 28 2021, 17:03:44)
有人可以帮我一下吗？
非常感谢